Copier

Abstract

 Electrical components in an elongated array are cantilevered within the interior of a closed loop rotatable photoconductor drum belt (205) of a compact copier. Some of the components are mounted on a board (233). A drive motor (225) is attached as part of the array and arranged to drive a fan (230) so that cooling air is forced through the sleeve of the belt and over the components, the sleeve acting as a plenum. Power can be coupled from the drive motor through end mounts to move the sleeve in the direction od its closed loop and provide power to other components of the copier.

Description

[0001] This invention relates to copiers having a closed loop photoconductive sleeve for rotary movement in the direction of the loop.

[0002] The invention provides improved means for positioning electrical components in such a copier. The invention seeks to ensure that maximum economy of volumetric space is realized.

[0003] There has been a continued interest for many years in designing and producing copier/duplicator machines which are adequately compact so that they can be used as a table-top device. An important concern in such machines is in maximizing utilization of the volumetric space within the frame covers. In systems wherein entire document images are placed on an elongated photoconductive surface which is typically formed as a closed loop belt or drum, the belt or drum must necessarily enclose a relatively large volumetric space, thereby demanding a considerable proportion of the interior volume of such a machine. These belts or drums are mounted for movement in their closed loop direction so as to receive the image from the original document and to pass through the various functional stages of-the copier for the purpose of transferring the received image to copy sheets.

[0004] The interior of the photoconductive belts or drums have been used for some purposes in prior art devices. For instance, rolls of photoconductive material have been positioned within the drums and arranged to be fed onto the peripheral surface of the drum and returned to take-up spools within the drum. In U.S. 3,642,368 is disclosed the mounting of optical elements and illumination lamps within transparent rotating drums so as to transfer images from one interior peripheral edge to an opposite edge, and the removal of heat from the lamps rotatably mounted within the drums by forcing cooling air coaxially through the drum. All such devices known in the prior art have attached the elements to the interior of the drum so that they rotate with the drum, thereby requiring slip ring power connections or the like, which is highly undesirable for reliability.

[0005] Although static mounting of electrical components within fixed cylindrical cans is disclosed in U.S. 2,876,277, none of the prior art is known to have statically suspended electrical components associated with the control and operation of a copier/duplicator within the internal environs of a moving photoconductive belt or a rotating-photoconductive drum.

[0006] The present invention is concerned with apparatus for mounting electrical components within a closed loop sleeve such as a movable belt or a rotatable drum in a manner which permits realization of maximum space utilization in a copier/duplicator machine. More particularly, the present invention relates to apparatus wherein a closed loop sleeve is mounted relative to the machine frame so that the sleeve can move in the direction of its closed loop. An elongated assembly, including a member having the electrical components associated with operation of the apparatus attached thereto, is arranged with transverse dimensions for fitting within the sleeve so as to allow the sleeve to move around the assembly member. The assembly is attached to the frame at at least one end of the sleeve so that it is securably received in suspended relation within the sleeve.

[0007] An additional and particularly advantageous feature of the present invention resides in including fan means mounted for driving cooling air through the sleeve and over the member with its electrical components so that the sleeve performs a dual function of both photoconductive surface support and plenum chamber for cooling of the components. A still further feature resides in including a drive motor with the assembly mounted in-line with the member. This drive motor can be arranged to power the fan blade for cooling and/or applying motivational power to the sleeve in the direction of the closed loop thereof or allowing power take- off to other elements associated with operation of the copier.

[0008] Accordingly, the present invention allows significant reduction in overall machine volume without significant extra part cost increase. It is particularly important for low cost office copiers configured as small, table-top machines.

[0009] The scope of the present invention is defined by the appended claims; and how it can be carried into effect is hereinafter particularly described with reference to the accompanying drawings, in which :-

FIG. 1 is an isometric view of a copier incorporating the present invention;

FIG. 2 is a side view, partially sectioned and partially schematic, of the copier of FIG. 1;

FIG. 3 is an isometric view in partially exploded relation illustrating the electrical component mounting arrangement within the photoconductive drum of the copier of FIGS. 1 and 2;

FIG. 4 is a plan view of part of the copier of FIG. 1;

FIG. 5 is an exploded and partially broken isometric view of another copier drum mounting assembly adapted for use with the present invention;

FIG. 6 is an isometric view of the spider plate end mount of the assembly of FIG. 5;

FIG. 7 is a side view, partially sectioned and partially schematic, of a portion of another copier according to the invention having a closed loop photoconductor sleeve or belt;

FIG. 8 is an isometric, broken away view of the electrical components mounting within the closed loop photoconductor belt or sleeve of the copier of FIG. 7.

[0010] A copier 10 (Fig. 1) has a mounting for a removable cassette 11 for paper copy sheets, slightly inclined to the vertical, whose front surface 31 provides a support for output copy sheets. The copier 10 also has an inclined feed slot 12 for original document entry and an output tray 18 for original documents after copying.

[0011] A cassette 11 (Fig. 2) containing a supply of copy sheets is initially inserted into the copier 10, after which original documents are introduced to the feed slot 12 by the user. An original document, by appropriate gating and drive rollers, is moved into the nip formed by a photoconductive drum 15 and a transparent roller 16 within which is positioned an illumination lamp 17.

[0012] Thus, as the original document which is inserted with the side to be copied facing drum 15, passes through the nip formed by drum 15 and roller 16, an image is electrostatically formed on the surface of drum 15. The original document is then either transferred to the output tray 18 or appropriately gated to recirculate a preselected number of times around a closed loop feed track 20.

[0013] The electrostatic image on the photoconductive surface of drum 15 passes a developer 22 where the image is developed and passes to a transfer corona 26. Copy sheets are fed from supply cassette 11 along path 25A to pass transfer corona 26, thereby receiving the developed image from the surface of drum 15. The copy sheet then is detached from drum 15 and delivered to the nip formed by fuser rollers 27 and 28, where the image is fixed to the copy sheet. The copy sheet is then delivered through output path 25B to a copy sheet output tray 30 accessible to the user. Longer length output copy sheets rest in part on the upper portion of the front surface 31. The driven surface then passes below corona 35, which provides'precharging of the photoconductive surface immediately prior to image transfer.

[0014] The copier 10 is a so-called two-cycle machine, in which the photoconductive surface of the drum 15 is effectively cleaned during one cycle and the image is transferred from an original document to a copy sheet during the next cycle. Thus the developer 22 which is a conventional magnetic brush-type device operates as a developer during the image transfer cycle, but as a cleaning device during the clean cycle. Conversely, coronas 26 and 35, as well as lamp 17 operate for appropriate transfer and/or cleaning charge functions during each of those two cycles as is well known in the art. The particular operation of the machine is exemplary only and forms no part of the present invention.

[0015] The copier 10 (FIG. 1) has a side panel 36 including a plurality of slots 37 which allow air to enter and/or exit from the interior of the machine. Slots 37 are arranged so as to be in general alignment with the axis of the drum 15 and a similar set of slots [not shown] are incorporated in a side panel 38 on the opposite side of the copier.

[0016] The copier has a frame with side plates 59 and 70 (Fig. 4). The drum 15 is mounted rotatably at one end on a bearing surface 62 (Fig. 3) formed as a flange integral with a collar 58 secured to the side plate 59 (Fig. 4) and aligned with a hole therein. The other end of the drum 15 is secured to a shoulder 77 (Fig. 3) on an annular gear assembly 72 having an external gear 76. The side plate 70 has a hole (not shown) aligned with the gear assembly 72 and carries an inner collar (not shown) with a bearing surface on which the gear assembly 72 can rotate.

[0017] An elongated assembly 40 (Fig. 3) of electrical components is suspended within the interior of drum 15, and includes a component mounting board 41 attached to which are typical electrical elements, such as tubular capacitors 42, 43 and 44, special purpose transformer 45, power transformer 46, and subassembly 48 which can include various circuit chips and the like, including a microprocessor. Board 41 has a notch therein over which is placed a moulded module assembly 50 which can be constructed similarly to that shown in the IBM Technical Disclosure Bulletin of May 1978 in the article entitled "Module Housing" by Ernst et al, at pages 5116 - 5117.

[0018] An interfacing plate 52 is retained in position by screws 53, 54 and 55 and standoffs, which cooperates with the notch in board 41 to hold board 41 in a channel 56 on the face of plate 52. These components are appropriately connected through various conductors into edge connector 57 for electrical communication outside of the end of the drum 15. The collar 58 includes gro6ves 60 and 61 for the purpose of retaining board 41 in its suspended position within drum 15.

[0019] The assembly 40 is completed by an attachment cage 64 and drive motor 65. Cage 64 is comprised of a plurality of L-shaped legs extending from interfacing plate 52 and attaching to the end face of drive motor 65. The L-shaped legs of assembly 64 form a protective cage around fan blades 66. Fan blades 66 are attached to the drive shaft 80 (Fig. 4) of motor 65. The stator of the motor 65 (Fig. 3) is supported from the side plate 70 (Fig. 4) by an X-shaped support 71 (Fig. 3) with a central aperture 81 for the shaft 80 (Fig. 4). Thus when the motor 65 is driven, the fan draws air through slots in the machine cover side panel, through the hole in the side plate 70, through the interior of the gear assembly 72 between the arms of the X-shaped support 71 and around the motor 65, through slots 73, 74, and 75 in the plate 52, around the assembly 50, over all the other electrical components associated with board 41, through the collar 58 and out of the slots in the other machine cover side panel. Drum 15 effectively provides an elongated plenum for air flow over assembly 40. Air filters can be included at any one or more locations between the inlet and exhaust slots in the side panels. The air flow could be be reversed.

[0020] The drive shaft 80 (Fig. 4) attached to motor 65 is coupled by gears 82 to 86 so as to drive gear 76 of assembly 72, and thus rotate drum 15 slowly around the electrical mounting assembly. Other power take offs can be arranged either by direct gearing or through clutches or the like for operating the developer/cleaner 22, the various drive rollers and other elements of copier 10. In an alternative embodiment of the invention shown in Figs. 5 and 6, a motor, fan and elongated electrical component assembly are mounted within a drum 111. The parts to mount the drum are of moulded configuration, and are used also to mount a magnetic brush roll spindle 111 forming part of the developer 22. Stub plate 115 includes a plurality of locating rivets 116 and 117 moulded integrally therewith to accurately locate plate 115 when inserted into pilot holes in a machine frame side plate. Rivets 116 and 117 can be hot upset to attach plate 115 to the machine frame side plate. Stub plate 115 has a main hole surrounded by a flange 125 with spring fingers 120, 121 and 122, which allow a gear and cam element 130 to be snapped into position on the surface of the flange 125 over fingers 120, 121 and 122 which retain the element 130 against lateral movement. The element 130 is then rotatable on the surface of the flange 125 of element 115. The plate 115 has an extension 126 with a projecting bearing support 128 to receive the rotating end of the magnetic brush roll spindle 111.

[0021] Unitary moulded element 130 has an external gear 132 engageable by a meshing drive gear [not shown] similar to that illustrated in FIG. 4. A first cam surface 133 provides paper path gate mechanism actuation. An index key 134 cooperates with a slot 112 in the drum 110 to positionally index drum shell 110 and to establish a rotary driving lug coupling. Spring tab 135 includes a radially extending external stub 136 for cooperation with a hole 113 in the drum 110 to provide positive drum positioning and allow the drum 110 to be removed by springing of tab 135. Grooves 137 and 138 provide lubricant and debris collecting operations.

[0022] Also moulded into the inner radial face of element 130 are emitter ring components to provide timing pulses for machine operation. A wide cam lobe 140 and a plurality of narrow cam lobes 141,-142 and 143 cooperate with stationary emitter switch 145 so that a "home" pulse is produced as cam 140 is sensed by switch 145, whereas lobes 141, 142 and 143 produce machine operation controlling pulses. Cam lobes 140, 142 and 143 are integrally moulded into the face of element 130, but may be made adjustable in a circumferential direction to correct timing pulse spacing.

[0023] The opposite ends of drum 110 and magnetic brush spindle 111 are mounted in a spider plate 150 (Fig. 6) which locates the drum centre line in relation to the magnetic roll of the magnetic brush developer. The plate 150 has an internal flange with a bearing surface 151, on which the drum 110 rotates, and which includes additional groves 152 and 153 for lubricant and debris collection. Slots 155 and 156 provide a guide and support for the printed circuit board similar to that illustrated in FIG. 3. Locating bosses 157 and 158 position spider plate 150 in holes in the machine frame side plate. Developer support boss 159 retains the other end of the magnetic brush roll spindle 111 in place and the keyed hole 160 therethrough locates a stationary portion of the spindle 111.

[0024] In yet another embodiment of the invention applied to a compactly configured copier 200 (Figs. 7 and 8), original documents are fed under a cover 201 so that they are gripped by the nip between rollers 202 and 203 to be moved past a scanning location where they are illuminated by dual lamps in a housing 204. The image is transferred to a photoconductive belt 205 through a fibre optic array 208. The original documents are then expelled from under cover 201 by rollers 210 and 211.

[0025] The photoconductive belt 205 is in the form of a closed loop or sleeve retained in position on a hollow extrusion housing 212 (FIG. 8). Housing 212 has a pair of elongated corner slots 213 and 214 with drive rollers 215 and 216 being rotatably mounted below slots 213 and 214, respectively, for allowing rollers 215 and 216 to engage the underside of belt 205. In addition, an outwardly biased tensioning bar 218 extends through another slot in the lower portion of housing 212 to apply slack removing tension to belt 205. The belt 205 is of a width so as to at least substantially cover slots 213 and 214. The copier includes a corona 219 (Fig. 7), a developer in a housing 220 and a paper path housing 221 which, because they do not form a part of this invention as such, will not be described further.

[0026] The extrusion housing 212 is attached to internal sidewall 222 (Fig. 8) of the copier 200 and includes means [not shown] for rotatably mounting drive rollers 215 and 216. A drive motor 225 is likewise attached to sidewall 222 with the drive shaft on one side thereof passing through wall 222 and being connected to gear 226. Gear 226 engages gear 227 which is coupled via shaft 228 back through wall 222 to provide motive power to drive roller 215. Thus, the closed loop belt or sleeve 205 is driven by roller 215 in the direction of its closed loop with roller 216 acting as an idler. The power drive output from gear 227 can be further coupled as to provide motive power to rollers 203 (Fig. 7) and 211.

[0027] At the opposite end of motor 225 the drive shaft is connected to a fan 230 which is partially encased by bracket 231. Other elements such as a start capacitor 232 and a printed circuit card 233, along with a usage meter 234 are all connected as a generally in-line assembly with motor 225. Although the assembly can be cantilevered within the interior of extruded housing 212 (FIG. 8), it is to be understood that an additional end plate [not shown] can be attached to the machine frame so as securely to receive edge 235 of the circuit card 233. Still further, slots are provided for allowing air flow through the interior of housing 212, through end wall 222, and filter elements may be included for filtering the air being driven through the plenum chamber formed by housing 212.

[0028] By the structure and structural interrelationships of the component mounting invention as described above for the preferred embodiments, a multiplicity of multiple functions is obtained from various elements and many advantages become available. The space within the drum or belt shell is fully utilized. The drive motor body becomes an integral structural member of the component mounting assembly and electronic packaging configuration. The fan for cooling the elements thus assembled can be directly attached to the motor shaft and provide cooling air flow with the drum or belt shell acting as a fan plenum when assembled. The drum or belt shell likewise acts as an electronic safety package shield and the printed circuit card and component module act as a drum or belt shell removal and assembly guide. Packaging within the drum or belt keeps electrical connections to a minimum for related savings. Heat from the motor and electronic package can assist for configurations where heater blankets are needed for the photoconductor or other requirements.

[0029] Although the present invention has been described with particularity relative to the foregoing detailed description of the exemplary preferred embodiments, various modifications, changes, additions, and applications of the present invention, in addition to those mentioned herein, will be readily apparent to those having normal skill in the art, without departing from the scope of this invention.

Claims

1. A copier having a closed loop photoconductive sleeve (15; 110; 205) mounted for rotary movement in the direction of the loop, characterised in that an elongated assembly (40) including a member (41; 233) having electrical components attached thereto, and having transverse dimensions for fitting within the sleeve so as to allow the sleeve to move around the member, is attached to a copier frame (70; 222) at least adjacent one end of the sleeve and cantilevered within the interior of the sleeve.

2. Apparatus according to claim 1, including a drive motor (65; 225) for the sleeve (15; 110; 205) mounted in-line with the member (41; 233) and within the interior of the sleeve.

3. Apparatus according to claim 2, in which the motor is coupled to a fan (66; 230) to draw air through the sleeve over the elongated assembly.

Drawing